WASHINGTON — In one of the toughest defeats of President Obama’s political career, the Senate this week sank a piece of gun control legislation that the White House had been laboring over for months. As the post-mortems of the loss begin, some have questioned if gun control got bogged down with the president’s ongoing struggle to effectively operate the levers of power in Washington.

Culprits for the bill’s demise are plenty — from gutless Senate moderates, to inflexible pro-gun conservatives, to a brazen gun lobby that waged an aggressive, and sometimes misleading, campaign to defeat the legislation.

But in the immediate aftermath of the defeat, critics have begun to second-guess Obama’s strategy and question whether he was fully prepared for what promised from the beginning to be a bruising battle with gun rights supporters.

White House allies defended the president’s efforts, and said his commitment to the issue was on full display throughout the process, noting that Obama, as well as Joe Biden, spent significant time directly engaging lawmakers and working the phones hard to try to jam through a last-minute bipartisan amendment to expand background checks for gun buyers.

“The White House worked hand in glove with all of the progressive gun and violence groups. They had conversations about strategy. And the president was out front on this. He’s really made a campaign out of promoting the position in a passionate way out in the public,” said Bob Creamer, president of Strategic Consulting Group, and a strategist who worked closely between progressive groups and the White House on guns.

“I don’t think there could have been any more engagement or commitment by the White House than they had on this issue,” Creamer said. A number of those involved in the process said it was hard to see how any White House could defeat the entrenched power of the NRA, and that Obama was willing to take a political risk and try.

But others said the White House’s campaign was encumbered by allowing urgency to fade; pursuing too many issues at once; overreaching in the early stages of the gun debate; and fundamentally failing to mobilize Obama’s legendary grassroots to pressure lawmakers.

Waiting too long

Obama acted fast after Newtown, declaring his intentions to seek new gun control regulations just days after the shooting. But then he created a commission to craft new proposals — the vast majority of which were old proposals favored by gun control advocates for decades, including the weapons ban Obama had sought since his first run for the presidency — which slowed things down.

One Democratic lobbyist with a long history on Capitol Hill said that if Obama had trimmed several weeks off the drafting process for legislation it’s possible legislation would have come before Congress when the public was still focused on Newtown.

“They screwed up. This thing was lost in March,” the lobbyist told BuzzFeed. “If [at the start of the session] they’d told Feinstein or whoever ‘You’ve got three weeks to produce a bill then it’s going to the floor,’ they could have had it.”

Sen. Joe Manchin, who led the final failed push for background checks in the Senate, sounded a similar note at a breakfast with reporters Thursday. The West Virginia Democrat’s bipartisan package was more conservative than many gun control advocates hoped they could get at the outset of the background check push, and Manchin said if advocates had been willing to take a less exciting bill at the outset, things could have gone another way.

“If we’d have gone to this bill, if we’d all gone to a bill like this immediately – boom,” Manchin said. Speaking of the period after the shootings when the public’s focus still on them full-time, Manchin said, “At that time we could have done something.”

Making Senate moderates choose between immigration and gun control

In the past four months, the White House has pressed moderate Republicans in the Senate to break with conservatives on both immigration reform and gun control — two extremely fraught issues — while, at the same time, they’ve had to explain their position on marriage equality amid a reignited culture war over gay rights.

Biden described the situation on an after-action conference call with gun control allies Thursday. (Press were not invited; a participant provided access to BuzzFeed.) Recalling the final push to get moderates off the fence on gun control, Biden said he found some Republicans making a choice: They could either cross their activist base on immigration or guns, but not both.

A political calculation was made, and the Senators decided immigration was the safer bet.

“They said, ‘Look, you can’t ask me to carry too much water here. You want me to do the right thing on immigration; I either can do that, or guns. I can’t do both of these things,’” Biden said. “‘On immigration, at least what will happen if I don’t the right way with immigration it’s going to cost me in my state. But if I don’t vote the right way with guns’ — they didn’t say ‘right way’ — ‘if I don’t vote on guns the way [you] want, they’re not going to punish me.’”

Manchin, a conservative Democrat who has laid most of the blame on the failure of his bill on a disinformation campaign by the NRA, echoed what Biden heard on the phone with Senators.

“They’ll evaluate it and say, ‘I can take on one fight, but do I need to take on two or three?’” he said of his fellow swing voting Senators. “How much energy do I have to sell two things?”

Asking for too much

Less than a month after the shootings in Newtown, Obama took the recommendations made by Biden’s task force to lay out an ambitious proposal for sweeping gun control legislation. The president made clear he wanted three key measures from Congress: A reinstated assault weapons ban, universal background checks on gun sales, and a 10-round limit on gun magazines.

Moments after the president outlined his proposal, gun control advocates rejoiced. The scale of the plan, they said, was comparable to the two biggest pushes for gun regulations in U.S. History — the Gun Control Act of 1986, and the Brady Handgun Violence Prevention Act of 1993.

“It’s really unprecedented in its scope and complexity,” Matt Bennett, of Third Way, told BuzzFeed at the time. “It’s on the level of the other two big gun safety movements we’ve seen in 1968 and 1993.”

But critics said the president asked for too much from a divided Congress, and spent too much time rallying the public around an overly ambitious, and perhaps even unrealistic, agenda.

Asked about the White House strategy on the gun push, Republican Sen. Lindsey Graham told BuzzFeed it “couldn’t have been any worse.”

“It’s tone deaf,” Graham said. “He’s been a political cheerleader on this, and he’s poisoned the well. There’s some solutions out there, but he picked three things that really wouldn’t fix the system.”

Graham added that the three measures Obama called for may have been what “the left wanted,” but they weren’t policies his Republican colleagues in the Senate believed would be effective.

“He’s played politics with this and quite frankly he lost because there’s more political rhetoric than substantive solutions,” Graham said. “The debate on the senate floor wasn’t about anybody being afraid [to vote for something] — it was about people looking at proposals that don’t address the problem.”

David Keene, the president of the National Rifle Association, made a similar point Thursday to The Washington Examiner, telling the paper that Obama had “bit off a lot more than he can chew.”

“He thought and his folks thought that Newtown changed everything. Newtown was a tragedy but that doesn’t change people’s basic values and feelings,” Keene said. “What he learned is that he bit off a lot more than he can chew and that you can’t just talk your way to a victory. You have to have something that makes some sense and he what he was proposing just didn’t make much sense.”

Even allies of the president acknowledge that if the measures in question had a stronger baseline of support in the Senate, the eleventh-hour phone calls from the president and vice president might have just swayed a last vote or two.

Asked why Sen. Heidi Heitkamp, the North Dakota Democrat, couldn’t be persuaded by the administration to vote yes on Manchin-Toomey, Creamer said, “I do think there might be a point where, if we had been closer, it might have been different — that may be the case. You’ve always got to take that into account,” he said.

Failing to mobilize gun control advocates

More than 91% of registered voters support universal background checks, according to a poll released earlier this month, but just 54 senators voted Wednesday for the measure.

Creamer volunteered that the Senate isn’t “really a Democratic body,” because each state, regardless of population, gets equal representation in the upper chamber. “You’ve got to realize what the Senate is and what it isn’t,” he said. “It’s not reflective of the population of the United States, and then add the filibuster, and suddenly you’ve got an unrepresentative body.”

But that an issue supported as widely as background checks couldn’t get through a Democratic-controlled Senate still confounds many.

“I think this has to do with the fact that you have a sickening display of a lack of political courage and I don’t think another phone call or a different person in the chief of staff position would have changed that. Ultimately that requires voters getting engaged,” Van Hollen told BuzzFeed.

Although major gun control groups rallied support for the bills, the movement certainly lacked the fervor of the Tea Party rallies of 2010.

The nonprofit organization, Organizing for Action, was founded with the promise to mobilize the public around the president’s agenda and push through his policy initiatives, but the group was one of the smaller players on the scene this spring, particularly relative to the Michael Bloomberg-headed Mayors Against Illegal Guns coalition.

Asked about the group’s role, Creamer described it as “substantial” while conceding that they weren’t fully operational.

“OFA is still getting up to speed, but they ran a couple of major days of action and generated a huge number of calls to members of Congress,” he said.

The organization will continue to play a major role, Creamer said, stressing the point that no matter what losses the White House suffered this week, the gun control fight was far from over.

“Getting 60 votes for anything is very, very hard, so I’m not at all surprised that we and the White House and all the forces in question fell a little short this time,” he said. “But we’ll be back.”